mongodb（一）-入门

参考：

http://www.yiibai.com/mongodb/

http://blog.csdn.net/yuwenruli/article/details/8529192

一、是什么

    mongodb是一个跨平台的，面向文档的数据库，提供高性能，高可用性和可扩展性方便。

    下面列出RDBMS术语与mongodb的关系：

     不适用场景：

     1、高度事务性系统

     2、复杂的跨表级查询

二、安装

    1. 下载相应版本的mongodb：mongodb-linux-x86_64-3.0.4

    2. 放到任意目录，比如：/home/mongodb-linux-x86_64-3.0.4

    3. 新建数据文件夹和日志文件：

[root@www mongodb-linux-x86_64-3.0.4]# mkdir data
[root@www mongodb-linux-x86_64-3.0.4]# touch logs

[root@www home]# cd mongodb-linux-x86_64-3.0.4/bin/
[root@www bin]# ./mongod --dbpath=/home/mongodb-linux-x86_64-3.0.4/data/ --logpath=/home/mongodb-linux-x86_64-3.0.4/logs --logappend --port=27017 --fork
about to fork child process, waiting until server is ready for connections.
forked process: 4528
child process started successfully, parent exiting

    --dbpath  数据库路径（数据文件）

    --logpath 日志文件路径

    --logappend 日志文件末尾增加

    --port 启用端口号

> use joan
switched to db joan
> db.dropDatabase()
{ "ok" : 1 }

     --fork 启用子进程运行

    用配置文件来启动：每次启动mongodb时，都要配置如此多参数，是不是有点太麻烦了？我们可以用配置文件来代替。

    配置文件内容：

dbpath = /home/mongodb-linux-x86_64-3.0.4/data
port = 27017
fork = ture
logappend = true
logpath = /home/mongodb-linux-x86_64-3.0.4/logs

Last login: Thu Jul 30 06:16:34 2015
[root@www ~]# cd /home/mongodb-linux-x86_64-3.0.4/
[root@www mongodb-linux-x86_64-3.0.4]# mkdir data/mongodb_27017
[root@www mongodb-linux-x86_64-3.0.4]# cd data/mongodb_27017/
[root@www mongodb_27017]# vi mongodb_27017.cnf
[root@www mongodb_27017]# cd ..
[root@www data]# cd ..
[root@www mongodb-linux-x86_64-3.0.4]# cd bin/
[root@www bin]# ./mongod -f /home/mongodb-linux-x86_64-3.0.4/data/mongodb_27017/mongodb_27017.cnf 
about to fork child process, waiting until server is ready for connections.
forked process: 2381
child process started successfully, parent exiting

    查看配置文件：

> use admin
switched to db admin
> db.runCommand({getCmdLineOpts:1})
{
	"argv" : [
		"./mongod",
		"-f",
		"/home/mongodb-linux-x86_64-3.0.4/data/mongodb_27017/mongodb_27017.cnf"
	],
	"parsed" : {
		"config" : "/home/mongodb-linux-x86_64-3.0.4/data/mongodb_27017/mongodb_27017.cnf",
		"net" : {
			"port" : 27017
		},
		"processManagement" : {
			"fork" : true
		},
		"storage" : {
			"dbPath" : "/home/mongodb-linux-x86_64-3.0.4/data"
		},
		"systemLog" : {
			"destination" : "file",
			"logAppend" : true,
			"path" : "/home/mongodb-linux-x86_64-3.0.4/logs"
		}
	},
	"ok" : 1
}

四、客户端连接

[root@www bin]# ./mongo
MongoDB shell version: 3.0.4
connecting to: test
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
	http://docs.mongodb.org/
Questions? Try the support group
	http://groups.google.com/group/mongodb-user
Server has startup warnings: 
2015-07-21T19:55:26.318+0800 I STORAGE  [initandlisten] 
2015-07-21T19:55:26.318+0800 I STORAGE  [initandlisten] ** WARNING: Readahead for /home/mongodb-linux-x86_64-3.0.4/data/ is set to 4096KB
2015-07-21T19:55:26.318+0800 I STORAGE  [initandlisten] **          We suggest setting it to 256KB (512 sectors) or less
2015-07-21T19:55:26.318+0800 I STORAGE  [initandlisten] **          http://dochub.mongodb.org/core/readahead
2015-07-21T19:55:26.551+0800 I CONTROL  [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.
2015-07-21T19:55:26.551+0800 I CONTROL  [initandlisten] 
2015-07-21T19:55:26.552+0800 I CONTROL  [initandlisten] 
2015-07-21T19:55:26.552+0800 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2015-07-21T19:55:26.552+0800 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2015-07-21T19:55:26.552+0800 I CONTROL  [initandlisten] 
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